JPH04349094A - Power steering device for outboard engine - Google Patents

Abstract

PURPOSE:To steer an outboard engine with a proper steering torque by generating the optimum assist force in accordance with the characteristics of the hull on which the outboard engine is mounted and also the running conditions of the boat. CONSTITUTION:A steering wheel is fitted with a steering torque sensor 24 to sense the steering load as a steering torque and an engine revolving speed sensor 25 to sense the revolving speed of an outboard engine, and is coupled with the body of outboard engine through a steering cable and a link mechanism. Further a power assist device 22 is provided to give an assist force to the link mechanism from a motor as an assist force generating source, and also a means is provided to decide the reference motor output current value on the basis of the engine revolving speed from the engine revolving speed sensor and the steering torque from the steering torque sensor. A controller 27 corrects this reference current value so that the steering torque during the outboard engine in steering lies within the optimum region, calculates the motor output current value supplied to the motor, and generates the optimum assist force in the power assist device.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Field of Industrial Application] The present invention relates to a power steering device for an outboard motor that power-assists the steering of an outboard motor. This invention relates to a steering device.

0003

2. Description of the Related Art Conventionally, there is a steering device for an outboard motor of this type which is constructed as shown in FIG. This steering device is operated manually, and when an operator operates a steering wheel 2 installed at the driver's seat of a hull 1, gears in a gear box 4 are rotated via a steering shaft 3. By the rotation of this gear, the inner cable 6 of the steering cable 5 moves forward or backward in its axial direction.

The steering cable 5 has an inner cable 6 housed within an outer cable 7, and the inner cable 6 is a push-pull cable. Furthermore, the steering cable 5 is connected from the gearbox 4 to
The outboard motor 8 is arranged to extend to the rear of the hull 1 where the outboard motor 8 is installed.

On the other hand, as shown in FIG. 11, the outboard motor 8 includes an outboard motor main body 1 provided with a drive shaft housing 9.
0, a swivel bracket 11 and a pair of left and right clamp brackets 12 are attached. The outboard motor main body 10 is connected to a swivel bracket 1 via a pilot shaft (not shown) fixed to the outboard motor main body 10.
1 so that it can rotate horizontally. The swivel bracket 11 is rotated vertically (
(tilt) supported. This clamp bracket 1
The outboard motor main body 10 is attached to the hull 1 by gripping the transom 1a of the hull 1.

[0006] The above steering cable 5 shown in FIG.
The outer cable 7 of the clamp bracket shaft 1
It is fixed to one end of 3. This clamp bracket shaft 13 has a hollow cylindrical shape, and the inner cable 6 passes through this clamp bracket shaft 13 and extends to the outside of the other end. A bent end of a drag link 15 of the link mechanism 14 is connected to the tip of the inner cable 6. The link mechanism 14 is configured by rotatably connecting a straight end of a substantially L-shaped drag link 15 and one end of a steering bracket 16. The other end of the steering bracket 16 is fixed to the outboard motor main body 10. Therefore, by operating the steering wheel 2 to push and pull the inner cable 6 of the steering cable 5, the outboard motor main body 10 is swung from side to side in the horizontal direction around the pilot shaft (not shown) via the link mechanism 14. The outer engine 8 is steered.

[0007]

[Problems to be Solved by the Invention] However, in the conventional manual steering device as described above, it is difficult to control the characteristics of the hull 1 such as the shape and weight of the hull 1 in which the outboard motor 8 is installed, wind, waves, and hull speed. There is a possibility that the steering load when steering the outboard motor 8 increases depending on the navigation conditions such as the above.

The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to reduce the steering load when operating the handle of an outboard motor by generating an assist force, and to reduce the steering load when operating the handle of an outboard motor. An object of the present invention is to provide a power steering device for an outboard motor that can generate an optimal assisting force according to the hull characteristics such as the shape and weight of the hull, as well as the hull conditions. [Structure of the invention]

[0009]

[Means for Solving the Problems] According to the present invention, a steering cable is operatively connected to a steering wheel installed on a boat hull, this steering cable is connected to an outboard motor body via a link mechanism, and the above-mentioned steering wheel The outboard motor main body is rotated horizontally with respect to the support bracket and steered by the steering load acting on the steering cable and the link mechanism, and the main part of the power steering device is installed on the support bracket. The power steering device includes a steering torque sensor that detects the steering load acting on the steering wheel as steering torque, an engine rotation speed sensor that detects the engine rotation speed of the outboard motor, and a steering torque sensor that is connected to the link mechanism. A reference motor output current value is determined based on a power assist device that applies an assist force, the steering torque from the above-mentioned steering torque sensor, and the engine speed from the above-mentioned engine speed sensor, and the steering torque during steering of the outboard motor is determined. a controller that corrects the reference motor output current value so that the reference motor output current value is in an optimal region, calculates a motor output current value to be supplied to the electric motor, and generates an optimal assist force in the power assist device;
It is characterized by having the following.

0010

[Operation] Generally, it is desirable that the steering torque be set at a value in the optimum range, neither too light nor too heavy. Furthermore, this steering torque is influenced by the shape of the hull in which the outboard motor is installed, hull characteristics such as flow rate, and navigation conditions such as wind and waves while the outboard motor is being steered. Therefore, when the steering torque is not in the optimum range, the controller corrects the reference motor output current so that the steering torque is in the optimum range, and the motor output current supplied to the electric motor of the power assist device. By optimizing this, the assist force generated by the power assist device can be automatically adapted to the hull characteristics and navigation conditions.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 4 is a horizontal sectional view of FIG. 3, showing a power assist device and the like in one embodiment of the power steering device for an outboard motor according to the present invention. In this embodiment, the same parts as those in the conventional example are given the same reference numerals and the explanation will be omitted.

As shown in FIG. 3, a power assist device 22 of a power steering device 21 is fixed by bolts 23 to the front (on the hull 1 side) of a swivel bracket 11 serving as a support bracket for the outboard motor 1. As shown in FIG. This power steering device 21 also includes a steering torque sensor 2.
4. The engine rotation speed sensor 25 and controller 27 shown in FIG. 1 are included.

As shown in FIG. 4, the power assist device 22 includes a rack 33, a pinion 34, and reduction gears 35, 36 connected to the pinion.
It is housed inside and configured. In particular, both ends of the rack 33 are covered by a retractable bellows case 32 fixed to a housing 37. The rack 33 is connected to the hull 1
The pinion 34 extends parallel to the width direction of the pinion 34 and meshes with the pinion 34. Further, the reduction gears 35 and 36 are bevel gears, and the reduction gear 36 is fixed to the shaft of the electric motor 38. The axis of the electric motor 38 is installed horizontally in the width direction of the hull 1. Additionally, an assist arm 3 is provided at one end of the rack 33.
9 is fixed, and this assist arm 39 is connected to the link mechanism 1.
It is attached to the drag link 15 of No. 4. In this installation situation, as shown in FIG. 41. Therefore, the pinion 34 is driven by the electric motor 38 in FIG.
rotates, the rack 33 moves linearly, and assist force is applied to the drag link 15 via the assist arm 39.

On the other hand, the steering torque 24 is bolted to the clamp bracket 12 by a fixing bracket 42 . Furthermore, this steering torque sensor 24 is connected to the outer cable 7 of the steering cable 5 via a sensor bracket 43. Therefore, when the driver operates the steering wheel 2 shown in FIG.
When the inner cable 6 of the steering cable 5 moves relative to the outer cable 7, the outer cable 7 shown in FIG. 4 receives a reaction force (steering load) from the inner cable 6.
The steering torque sensor 24 detects this steering load using a potentiometer or the like and transmits it to the controller 27 as a steering torque signal.

[0016] Furthermore, the engine rotation speed sensor 2 shown in FIG.
5 detects the rotation speed of an engine (not shown) mounted in the outboard motor main body 10 and transmits an engine rotation speed signal to the controller 27 .

Furthermore, as shown in FIG.
, torque control signal circuit 47 and PWM (PU
LSEWIDTH MODULE) control unit 48 and the like. The calculation unit 44 performs calculations described below to determine the current value to be supplied to the electric motor 38. The current value signal to the electric motor 38 set by the calculation unit 44 is processed by the torque control signal output circuit 47 and the PWM control unit 48.
The power drive section 49 is reached. This power drive section 4
9 amplifies the current value signal from the controller 27 in order to drive the electric motor 38 and outputs it to the motor 38 .

Now, the calculations performed by the calculation section 44 will be described below. First, the calculation unit 44 is provided with a ROM (READ ONLY MEMORY) that stores a data map. There are at least two types of data maps, one of which is a reference motor output current map shown in FIG. 6, and the other one is a torque region map shown in FIG.

The reference motor output current map is based on the steering torque detected by the steering torque sensor 24 (same meaning as the torque sensor output value in FIG. 6) and the engine rotation speed detected by the engine rotation speed sensor 25. This is a data map of the motor output current that serves as a reference to be determined. When the torque sensor output value is (2.5+α)V or more, the outboard motor is steered to the right, and when the torque sensor output value is (2.5−α)V or less, the outboard motor is steered to the left. Torque sensor output value is (2.5+α)V
The reference motor output current value is set larger as the engine speed approaches 5.0V or from (2.5-α)V to 0V, or as the engine speed becomes lower.

[0020] The torque range map also divides the range from the torque sensor output value (2.5+α)V to 5.0V when the outboard motor is steered to the right into three torque ranges RA and R at approximately equal intervals.
Similarly, the torque range from the torque sensor output value (2.5-α)V to 0V when the outboard motor is steered to the left is divided into three torque ranges LA, LB, and LC. . Each of the above torque ranges RA, RB, RC, LA, L
B and LC are further subdivided by engine speed.

The calculation unit 44 calculates that the sensor torque output value from the steering torque sensor 24 is (2.5+α)V or more or (
2.5-α) When the motor output current becomes equal to or less than V, the motor output current is calculated based on the following equation (2), and this motor output current value is output to the electric motor 38 of the power assist device 22.

(Motor output current) = (Reference motor output current)
× (correction coefficient)......■The correction coefficient in this formula (■correction coefficient γ when steering to the right, correction coefficient δ when steering to the left) is independent of the engine rotation speed, and is independent of the engine speed, as shown in Figs.
It is determined according to the flowchart shown in .

In other words, the calculation unit 44 sets the initial values of the correction coefficients γ and δ to 1, and further calculates the number of times each torque region of the torque region map shown in FIG. 7 is searched (each torque region counter).
The total number of each torque region counter (total number counter) is initially set to 0. In this state, when the torque sensor output value becomes (2.5+α)V or more or (2.5-α)V or less, the calculation unit 44 calculates that the torque sensor output value is in the RA torque region of the torque region map. RB torque area, RC torque area, or LA torque area,
A search is made to see if it is in either the LB torque region or the LC torque region, and the number of searches is counted. Search is performed until the total number of counters reaches β times, and the correction coefficient γ is set according to the type of torque region with the largest number of searches (number of counters).
, δ are determined.

For example, if the torque sensor output value is (2.5+
α) When steering to the right by V or more, the calculation unit 44 determines whether the torque region at the time of the first counter is the RA torque region, the RB torque region, or the RC torque region. If it is in the RA torque area, add 1 to the RA torque area counter to change the RA torque area count value,
If it is an RB or RC torque region, 1 is added to each of the RB or RC torque region counters to change the respective torque region counter values. At the same time, 1 is also added to the total number counter to change the total number counter value. The determination of the torque region and the change of the counter value are carried out until the total number of counters reaches β times, and when the total number of counters reaches β times, the torque region with the largest number of counters is determined.

When the torque region with the largest number of counters is the RB torque region, the correction coefficient γ is maintained at 1 because the steering torque is optimal. Furthermore, when the torque region with the highest number of counters is the RA torque region, the output current to the electric motor 38 is excessive, the assist force is too large, and the steering torque is too light, so 0.1 is subtracted from the correction coefficient γ. A new correction coefficient γ is calculated. Furthermore, when the torque region with the largest number of counters is the RC torque region, the output current to the electric motor 38 is too small, the assist force is too small, and the steering torque is too large, so 0.1 is added to the correction coefficient γ. Then, a new correction coefficient γ is calculated.

When the total number of counters reaches β times, the calculation unit 44 obtains the reference motor output current from the reference motor output current map shown in FIG. 6, and calculates the new correction coefficient γ determined as described above. Based on formula ■, electric motor 38
Calculate the motor output current supplied to the

While the outboard motor is being steered to the right, the above calculation continues, so after calculating the motor output current, reset both the torque area counter and total number counter to 0, and repeat the same procedure. Calculate the correction coefficient γ after the total number of counters β times, and calculate the motor output current again from equation (2). While the outboard motor is being steered to the right, the motor output current is repeatedly calculated in this way, and the assist force generated by the power assist device 22 is automatically controlled.

Even in the case of left steering of the outboard motor where the torque sensor output value is less than (2.5-α)V, the calculation unit 44 operates the electric motor 38 in the same way as for right steering as shown in FIG. The assist force generated by the power assist device 22 is automatically controlled by repeatedly calculating the output current to the power assist device 22.

As described above, the calculation unit 44 calculates that the RB torque area counter value is RA, while the outboard motor is being steered to the right.
The correction coefficient γ is changed so that it becomes larger than the RC torque region counter value, and the motor output current value is calculated from the changed correction coefficient γ and the reference motor output current value using equation (2). Also, when the outboard motor is being steered to the left, the correction coefficient δ is changed so that the LB torque area counter value is larger than the LA and LC torque area counter values, similarly to when the outboard motor is being steered to the right.
From the modified correction coefficient δ and the reference motor output current value, the motor output current value is calculated using equation (3).

Note that if the outboard motors are installed in the same hull, the above correction coefficients γ and δ can be backed up in the calculation section 44 of the controller 27 after the outboard motors are stopped, and used next time. The initial values of correction coefficients γ and δ are not set to 1 while the outboard motor is operating, and the correction coefficients γ and δ backed up last time are
The value of can be used as the initial value.

Furthermore, the power assist device 22 shown in FIG.
, the abnormality detection unit 47 detects each sensor 24, 25,
When a lead wire such as 26 is cut and an unusual signal is output from each sensor 24, 25, 26, etc., the signal is output to the calculation unit 44 as an abnormality. When this abnormality signal is input to the calculation section 44, a fail-safe signal is output from the calculation section 44 to the torque control signal output circuit 47. At this time, the torque control signal output circuit 47 reduces the current value signal of the electric motor 38 by half or cuts it off. In this way, controller 2
7 also executes control in the event of an abnormality.

According to the above embodiment, the calculation section 44 of the controller 27 calculates the steering torque detected by the torque sensor 24 because it is influenced by the hull characteristics such as the shape and weight of the hull, as well as the purpose of navigation of the hull. The correction coefficients γ and δ are determined so that most of this steering torque is in the optimum RB or LB torque region, and the motor output current value supplied to the electric motor 38 is automatically changed. As a result, the assist force generated by the power assist device 22 can be optimized for the hull characteristics and navigation purpose, and the outboard motor can be steered with an appropriate steering torque.

[0033]

As described above, the power steering device for an outboard motor according to the present invention includes a steering torque sensor that detects the steering load acting on the steering wheel as a steering torque, and a steering torque sensor that detects the steering load acting on the steering wheel as a steering torque. a power assist device that is connected to a link mechanism and applies an assisting force to the link mechanism; and a power assist device that is connected to the link mechanism and applies an assist force to the link mechanism, based on the steering torque from the steering torque sensor and the engine rotation speed from the engine rotation speed sensor. Determine the reference motor output current value using Since the present invention has a controller that causes the power assist device to generate an assist force, it is possible to automatically generate an optimum assist force according to the characteristics of the hull in which the outboard motor is installed, navigation conditions, etc.

[Brief explanation of drawings]

FIG. 1 is a block diagram mainly showing a controller in an embodiment of a power steering device for an outboard motor according to the present invention.

FIG. 2 is a side view showing an outboard motor to which the power steering device of FIG. 1 is applied.

FIG. 3 is a view from arrow III in FIG. 2;

FIG. 4 is a horizontal sectional view of the power assist device of FIG. 3.

FIG. 5 is an enlarged perspective view of the V section in FIG. 4;

FIG. 6 is a diagram showing a reference motor output current map.

FIG. 7 is a diagram showing a torque region current map.

FIG. 8 is a flowchart for determining a correction coefficient γ in the calculation unit of FIG. 1;

FIG. 9 is a flowchart for determining a correction coefficient δ in the calculation unit of FIG. 1;

FIG. 10 is a perspective view showing a conventional steering device for an outboard motor.

FIG. 11 is a side view of an outboard motor to which the steering device of FIG. 10 is applied.

[Explanation of symbols]

1 Hull 2 Steering wheel 5 Steering cable 10 Outboard motor body 14 Link mechanism 15 Drug Link 16 Steering bracket 22 Power assist device 24 Steering torque sensor 25 Engine speed sensor 27 Controller 38 Electric motor 44 Arithmetic unit γ, δ correction coefficient

Claims (1)

[Claims] Claim 1: A steering cable is operatively connected to a steering wheel installed on the hull, the steering cable is connected to the outboard motor body via a link mechanism, and the steering is controlled by a steering load acting on the steering wheel. The outboard motor body is steered by rotating horizontally relative to the support bracket via cables and link mechanisms, and the main part of the power steering device is installed on the support bracket, and this power steering device is connected to the steering wheel. A steering torque sensor that detects the applied steering load as steering torque, an engine rotation speed sensor that detects the engine rotation speed of the outboard motor, and a power assist device that is connected to the link mechanism and applies an assist force to the link mechanism. Then, a reference motor output current value is determined based on the steering torque from the steering torque sensor and the engine rotation speed from the engine rotation speed sensor, and the reference motor output current value is determined so that the steering torque during steering of the outboard motor is in the optimum range. A controller for correcting a reference motor output current value to calculate a motor output current value to be supplied to the electric motor, and causing the power assist device to generate an optimal assist force. Steering device.